Your blog is coming up correctly now... at least I don't see any error messages.

ASP.NET usually needs to monitor certain files. One of them is the web.config file. If it doesn't have sufficient permissions to access a file, I think that is when that error message appears.

There could be another cause for the error as well. I don't think I've ever seen that error message in the BlogEngine Discussions before. But it did show up in Google results, for other people using ASP.NET. So for finding an answer (in
case the problem persists), I think your best bet is to see what other people tried doing.